LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 108

Search options

  1. Article ; Online: Single-cell evidence for plasmid addiction mediated by toxin-antitoxin systems.

    Fraikin, Nathan / Van Melderen, Laurence

    Nucleic acids research

    2024  Volume 52, Issue 4, Page(s) 1847–1859

    Abstract: Toxin-antitoxin (TA) systems are small selfish genetic modules that increase vertical stability of their replicons. They have long been thought to stabilize plasmids by killing cells that fail to inherit a plasmid copy through a phenomenon called post- ... ...

    Abstract Toxin-antitoxin (TA) systems are small selfish genetic modules that increase vertical stability of their replicons. They have long been thought to stabilize plasmids by killing cells that fail to inherit a plasmid copy through a phenomenon called post-segregational killing (PSK) or addiction. While this model has been widely accepted, no direct observation of PSK was reported in the literature. Here, we devised a system that enables visualization of plasmid loss and PSK at the single-cell level using meganuclease-driven plasmid curing. Using the ccd system, we show that cells deprived of a ccd-encoding plasmid show hallmarks of DNA damage, i.e. filamentation and induction of the SOS response. Activation of ccd triggered cell death in most plasmid-free segregants, although some intoxicated cells were able to resume growth, showing that PSK-induced damage can be repaired in a SOS-dependent manner. Damage induced by ccd activates resident lambdoid prophages, which potentiate the killing effect of ccd. The loss of a model plasmid containing TA systems encoding toxins presenting various molecular mechanisms induced different morphological changes, growth arrest and loss of viability. Our experimental setup enables further studies of TA-induced phenotypes and suggests that PSK is a general mechanism for plasmid stabilization by TA systems.
    MeSH term(s) Bacterial Toxins/genetics ; Bacterial Toxins/metabolism ; Plasmids/genetics ; Toxin-Antitoxin Systems ; Bacteria/genetics
    Chemical Substances Bacterial Toxins
    Language English
    Publishing date 2024-01-15
    Publishing country England
    Document type Journal Article
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkae018
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 1067: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: iTDtest: an Easy-to-Handle and Visual Assay To Detect Tolerant and Persister Cells in an Antibiotic Combination Regimen.

    Van Melderen, Laurence

    mBio

    2022  Volume 13, Issue 3, Page(s) e0036222

    Abstract: In a recent article, Balaban and colleagues developed the iTDtest allowing characterization of the type of interactions between different antibiotics at bactericidal concentrations (J.-F. Liu et al., mBio 13:e00004-22, 2022). This visual and ... ...

    Abstract In a recent article, Balaban and colleagues developed the iTDtest allowing characterization of the type of interactions between different antibiotics at bactericidal concentrations (J.-F. Liu et al., mBio 13:e00004-22, 2022). This visual and semiquantitative assay is designed to determine how antibiotic cocktails affect tolerance and persistence, two phenomena of major importance for the eradication of difficult-to-treat pathogens. Importantly, Balaban and colleagues identified antibiotic combinations allowing for complete clearance of persister and tolerant cells. This commentary discusses the translation of this assay in clinical settings, where antibiotic combination therapies appear to be applied in specific contexts, such as in acute infections or in the case of multidrug or extensively drug-resistant pathogens.
    MeSH term(s) Anti-Bacterial Agents/pharmacology ; Anti-Bacterial Agents/therapeutic use ; Drug Tolerance ; Microbial Sensitivity Tests
    Chemical Substances Anti-Bacterial Agents
    Language English
    Publishing date 2022-06-13
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Comment
    ZDB-ID 2557172-2
    ISSN 2150-7511 ; 2161-2129
    ISSN (online) 2150-7511
    ISSN 2161-2129
    DOI 10.1128/mbio.00362-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article ; Online: Are envelope stress responses essential for persistence to β-lactams in

    Rousseau, Clothilde J / Fraikin, Nathan / Zedek, Safia / Van Melderen, Laurence

    Antimicrobial agents and chemotherapy

    2023  Volume 67, Issue 10, Page(s) e0032923

    Abstract: Bacterial persistence to antibiotics defines the ability of small sub-populations of sensitive cells within an isogenic population to survive high doses of bactericidal antibiotics. Here, we investigated the importance of the five main envelope stress ... ...

    Abstract Bacterial persistence to antibiotics defines the ability of small sub-populations of sensitive cells within an isogenic population to survive high doses of bactericidal antibiotics. Here, we investigated the importance of the five main envelope stress responses (ESRs) of
    MeSH term(s) Escherichia coli ; beta-Lactams/pharmacology ; Meropenem ; Anti-Bacterial Agents/pharmacology ; Escherichia coli Proteins/genetics
    Chemical Substances beta-Lactams ; Meropenem (FV9J3JU8B1) ; Anti-Bacterial Agents ; Escherichia coli Proteins
    Language English
    Publishing date 2023-10-03
    Publishing country United States
    Document type Journal Article
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/aac.00329-23
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 809: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)
    Einzelsignatur: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article ; Online: TisB protein is the single molecular determinant underlying multiple downstream effects of ofloxacin in

    Cayron, Julien / Oms, Thierry / Schlechtweg, Tatjana / Zedek, Safia / Van Melderen, Laurence

    Science advances

    2024  Volume 10, Issue 13, Page(s) eadk1577

    Abstract: Bactericidal antibiotics can cause metabolic perturbations that contribute to antibiotic-induced lethality. The molecular mechanism underlying these downstream effects remains unknown. Here, we show that ofloxacin, a fluoroquinolone that poisons DNA ... ...

    Abstract Bactericidal antibiotics can cause metabolic perturbations that contribute to antibiotic-induced lethality. The molecular mechanism underlying these downstream effects remains unknown. Here, we show that ofloxacin, a fluoroquinolone that poisons DNA gyrase, induces a cascade of metabolic changes that are dependent on an active SOS response. We identified the SOS-regulated TisB protein as the unique molecular determinant responsible for cytoplasmic condensation, proton motive force dissipation, loss of pH homeostasis, and H
    MeSH term(s) Escherichia coli/metabolism ; Ofloxacin/pharmacology ; Escherichia coli Proteins/chemistry ; DNA Gyrase/metabolism ; DNA Gyrase/pharmacology ; Hydrogen Peroxide/metabolism ; Anti-Bacterial Agents/pharmacology ; Anti-Bacterial Agents/metabolism
    Chemical Substances Ofloxacin (A4P49JAZ9H) ; Escherichia coli Proteins ; DNA Gyrase (EC 5.99.1.3) ; Hydrogen Peroxide (BBX060AN9V) ; Anti-Bacterial Agents
    Language English
    Publishing date 2024-03-27
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.adk1577
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  5. Article ; Online: Population and Single-Cell Analysis of Antibiotic Persistence in Escherichia coli.

    Oms, Thierry / Schlechtweg, Tatjana / Cayron, Julien / Van Melderen, Laurence

    Journal of visualized experiments : JoVE

    2023  , Issue 193

    Abstract: Antibiotic persistence refers to the capacity of small bacterial subpopulations to transiently tolerate high doses of bactericidal antibiotics. Upon bactericidal antibiotic treatment, the bulk of the bacterial population is rapidly killed. This first ... ...

    Abstract Antibiotic persistence refers to the capacity of small bacterial subpopulations to transiently tolerate high doses of bactericidal antibiotics. Upon bactericidal antibiotic treatment, the bulk of the bacterial population is rapidly killed. This first rapid phase of killing is followed by a substantial decrease in the rate of killing as the persister cells remain viable. Classically, persistence is determined at the population level by time/kill assays performed with high doses of antibiotics and for defined exposure times. While this method provides information about the level of persister cells and the killing kinetics, it fails to reflect the intrinsic cell-to-cell heterogeneity underlying the persistence phenomenon. The protocol described here combines classical time/kill assays with single-cell analysis using real-time fluorescence microscopy. By using appropriate fluorescent reporters, the microscopy imaging of live cells can provide information regarding the effects of the antibiotic on cellular processes, such as chromosome replication and segregation, cell elongation, and cell division. Combining population and single-cell analysis allows for the molecular and cellular characterization of the persistence phenotype.
    MeSH term(s) Anti-Bacterial Agents/pharmacology ; Escherichia coli/genetics ; Bacteria ; Cell Division ; Single-Cell Analysis/methods
    Chemical Substances Anti-Bacterial Agents
    Language English
    Publishing date 2023-03-24
    Publishing country United States
    Document type Journal Article ; Video-Audio Media ; Research Support, Non-U.S. Gov't
    ZDB-ID 2259946-0
    ISSN 1940-087X ; 1940-087X
    ISSN (online) 1940-087X
    ISSN 1940-087X
    DOI 10.3791/64550
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  6. Article ; Online: Shear-enhanced sorting of ovoid and filamentous bacterial cells using pinch flow fractionation.

    de Timary, Guillaume / Rousseau, Clothilde J / Van Melderen, Laurence / Scheid, Benoit

    Lab on a chip

    2023  Volume 23, Issue 4, Page(s) 659–670

    Abstract: In this paper, we experimentally investigate the influence of the flow rate on the trajectory of ovoid and filamentous bacterial cells ... ...

    Abstract In this paper, we experimentally investigate the influence of the flow rate on the trajectory of ovoid and filamentous bacterial cells of
    MeSH term(s) Escherichia coli ; Rotation ; Cell Movement
    Language English
    Publishing date 2023-02-14
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2056646-3
    ISSN 1473-0189 ; 1473-0197
    ISSN (online) 1473-0189
    ISSN 1473-0197
    DOI 10.1039/d2lc00969b
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  7. Article: The Variety in the Common Theme of Translation Inhibition by Type II Toxin-Antitoxin Systems.

    Jurėnas, Dukas / Van Melderen, Laurence

    Frontiers in genetics

    2020  Volume 11, Page(s) 262

    Abstract: Type II Toxin-antitoxin (TA) modules are bacterial operons that encode a toxic protein and its antidote, which form a self-regulating genetic system. Antitoxins put a halter on toxins in many ways that distinguish different types of TA modules. In type ... ...

    Abstract Type II Toxin-antitoxin (TA) modules are bacterial operons that encode a toxic protein and its antidote, which form a self-regulating genetic system. Antitoxins put a halter on toxins in many ways that distinguish different types of TA modules. In type II TA modules, toxin and antitoxin are proteins that form a complex which physically sequesters the toxin, thereby preventing its toxic activity. Type II toxins inhibit various cellular processes, however, the translation process appears to be their favorite target and nearly every step of this complex process is inhibited by type II toxins. The structural features, enzymatic activities and target specificities of the different toxin families are discussed. Finally, this review emphasizes that the structural folds presented by these toxins are not restricted to type II TA toxins or to one particular cellular target, and discusses why so many of them evolved to target translation as well as the recent developments regarding the role(s) of these systems in bacterial physiology and evolution.
    Language English
    Publishing date 2020-04-17
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2606823-0
    ISSN 1664-8021
    ISSN 1664-8021
    DOI 10.3389/fgene.2020.00262
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  8. Article ; Online: Phenotypic Characterization of Antibiotic Persisters at the Single-Cell Level: From Data Acquisition to Data Analysis.

    Fraikin, Nathan / Van Melderen, Laurence / Goormaghtigh, Frédéric

    Methods in molecular biology (Clifton, N.J.)

    2021  Volume 2357, Page(s) 95–106

    Abstract: Persister cells are present at low frequency in isogenic populations. Moreover, they are only distinguishable from the bulk at the recovery time, after the antibiotic treatment. Therefore, time-lapse microscopy is the gold-standard method to investigate ... ...

    Abstract Persister cells are present at low frequency in isogenic populations. Moreover, they are only distinguishable from the bulk at the recovery time, after the antibiotic treatment. Therefore, time-lapse microscopy is the gold-standard method to investigate this phenomenon. Here, we describe an exhaustive procedure for acquiring single-cell data which is particularly suitable for persister cell analysis but could be applied to any other fields of research involving single-cell time-lapse microscopy. In addition, we discuss the challenges and critical aspects of the procedure with respect to the generation of robust data.
    MeSH term(s) Anti-Bacterial Agents/pharmacology ; Data Analysis ; Escherichia coli
    Chemical Substances Anti-Bacterial Agents
    Language English
    Publishing date 2021-09-26
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-0716-1621-5_7
    Database MEDical Literature Analysis and Retrieval System OnLINE

    Full text online

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Article ; Online: Biology and evolution of bacterial toxin-antitoxin systems.

    Jurėnas, Dukas / Fraikin, Nathan / Goormaghtigh, Frédéric / Van Melderen, Laurence

    Nature reviews. Microbiology

    2022  Volume 20, Issue 6, Page(s) 335–350

    Abstract: Toxin-antitoxin systems are widespread in bacterial genomes. They are usually composed of two elements: a toxin that inhibits an essential cellular process and an antitoxin that counteracts its cognate toxin. In the past decade, a number of new toxin- ... ...

    Abstract Toxin-antitoxin systems are widespread in bacterial genomes. They are usually composed of two elements: a toxin that inhibits an essential cellular process and an antitoxin that counteracts its cognate toxin. In the past decade, a number of new toxin-antitoxin systems have been described, bringing new growth inhibition mechanisms to light as well as novel modes of antitoxicity. However, recent advances in the field profoundly questioned the role of these systems in bacterial physiology, stress response and antimicrobial persistence. This shifted the paradigm of the functions of toxin-antitoxin systems to roles related to interactions between hosts and their mobile genetic elements, such as viral defence or plasmid stability. In this Review, we summarize the recent progress in understanding the biology and evolution of these small genetic elements, and discuss how genomic conflicts could shape the diversification of toxin-antitoxin systems.
    MeSH term(s) Antitoxins/genetics ; Bacteria/genetics ; Bacterial Proteins/genetics ; Genome, Bacterial ; Genomics ; Toxin-Antitoxin Systems/genetics
    Chemical Substances Antitoxins ; Bacterial Proteins
    Language English
    Publishing date 2022-01-02
    Publishing country England
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 2139054-X
    ISSN 1740-1534 ; 1740-1526
    ISSN (online) 1740-1534
    ISSN 1740-1526
    DOI 10.1038/s41579-021-00661-1
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 5865: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)
    Zs.MG 74: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  10. Article ; Online: Single-cell imaging and characterization of

    Goormaghtigh, Frédéric / Van Melderen, Laurence

    Science advances

    2019  Volume 5, Issue 6, Page(s) eaav9462

    Abstract: Bacterial persistence refers to the capacity of small subpopulations within clonal populations to tolerate antibiotics. Persisters are thought to originate from dormant cells in which antibiotic targets are less active and cannot be corrupted. Here, we ... ...

    Abstract Bacterial persistence refers to the capacity of small subpopulations within clonal populations to tolerate antibiotics. Persisters are thought to originate from dormant cells in which antibiotic targets are less active and cannot be corrupted. Here, we report that in exponentially growing cultures, ofloxacin persisters originate from metabolically active cells: These cells are dividing before the addition of ofloxacin and do endure DNA damages during the treatment, similar to their nonpersister siblings. We observed that growth rate, DNA content, and SOS induction vary among persisters, as in the bulk of the population and therefore do not constitute predictive markers for persistence. Persister cells typically form long polynucleoid filaments and reach maximum SOS induction after removal of ofloxacin. Eventually, cell division resumes, giving rise to a new population. Our findings highlight the heterogeneity of persister cells and therefore the need to analyze these low-frequency phenotypic variants on a case-by-case basis at the single-cell level.
    MeSH term(s) Anti-Bacterial Agents/pharmacology ; Cell Division/drug effects ; DNA Damage/drug effects ; Escherichia coli/drug effects ; Escherichia coli/genetics ; Microbial Viability/drug effects ; Ofloxacin/pharmacology ; Single-Cell Analysis/methods
    Chemical Substances Anti-Bacterial Agents ; Ofloxacin (A4P49JAZ9H)
    Language English
    Publishing date 2019-06-19
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.aav9462
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top